1. Field of the Invention
The present invention relates to a reactor to be applied to PCR for nucleic acid amplification and, more particularly, to a reactor capable of accurate temperature control.
2. Description of the Related Art
In the case where it is necessary to control reactions according to temperature conditions, it is desirable to be able to control the temperature conditions more accurately. Capability of accurate temperature control is desirable for any reactors for liquids, solids, and gases. This holds true in the technical field of gene analysis.
One example of such cases is PCR (polymerase chain reaction) for nucleic acid amplification. PCR may be regarded as the standard process for quantitative analysis of nucleic acid in trace amounts.
PCR is designed to repeat the cycle of amplification, which consists of “thermal denaturation→annealing with primer→polymerase extension reaction,” thereby amplifying the amount of DNA several hundred thousand times.
The PCR amplified product obtained in this manner can be monitored in real time for quantitative analysis of nucleic acid in trace amounts.
However, PCR requires that the amplification cycle be accurately controlled. To this end, a highly accurate temperature control is essential.
Inadequate temperature control will lead to amplification of unnecessary DNA sequence or prevent amplification.
Thus, the above-mentioned reactor needs capability of highly accurate temperature control as a reactor. Technologies relating to this are disclosed in Japanese Patent Laid-open No. 2003-298068 and Japanese Patent Laid-open No. 2004-025426.
Control of heat generation in a minute region is accomplished by means of semiconductor devices. Semiconductor devices can be applied to heater elements arranged in matrix form. The technology relating to matrix arrangement is disclosed in Japanese Patent Laid-open No. 2003-180328.